Concentrating-table.



E. B. KIRBY.

GONOENTBATING TABLE.

APPLICATION FILED 11.20, 1903.

1,105,91 2, Patented Aug. 4, 1914.

4 SHEETS-SHEET 1.

WICJIGJYSE 'hvenior: 42. 3.1%.? Q

ggufl l Wm THE NORRIS PETERS CO PHOm-LITHO.. WASHINGTON, D. C;

E. B. KIRBY.

CONGBNTRATING TABLE.

APPLICATION IILBD APILZO, 190a.

Patented Aug. 4, 1914 4 BHBETB-SHEET 3.

Minedded.

B. B. KIRBY.

CONOENTRATING TABLE.

APPLICATION FILED APR. 20, 1903.

1,105,912, Patented Aug.4, 1914.

4 BHBET8-SEEET 4.

EDMUND IBJKIRBY, F ROSSLAND, BRITISH COLUMBIA, CAN ADA.

CONCENTRATING-TAIBLE. r

all'whom it may concern:

'Be it known" that I, EDMUND B. Kinny, a

- citizen of the United States, residing at Rossland, in the Province of British Columbia, Canada, have invented a certain new and useful Improvement in Concentrating- Tabl-es, of which the following ls a full,

clear, and exact description, reference being used in miningoperations forseparating;

had tothe accompanying drawings. a a

This inventlon relates to a general class of concentrating machlnes which are widely the n ineral or valuable portion oflore from the worthless portion or gangue. The ore, crushed so as to break it up into particles, is subjected, in the particular machines to which my invention applies, to two forces, one operating primarily on the heavy particles and the other on the light particles. Such a machine is best embodied in a table which is given a longitudinal 3 shake or bumpmore sudden in one direction than the other, and also is subjected tothe actionof wash water in a lateral direction. The effect of the bump or ,unequalshake is not only to keep the particles from, packing, but to settle the heavier particles downto the lower part of the layer and hence nearer to the table and cause such heavier particles to travel along thesurface more rapidly than the lighter particles, while the eti'ectvof 1 the wash water is to carry the lighter particles crosswise of the table. The tendency 0f the heavier particles is thus to travel longitudinally and of the lighter pars ticles to travel laterally and the result is that the particles takea diagonal direction and gradually become separated into lines of consecutively varying specific gravity and richness. Familiar instances of such a table are the Wilfiey concentrating table,

the Cammet table, the Overstrom table, and

the Rittinger table. The present invention is not limited to any particular design of table. Itis shown herein as applied to a table of, the l/Vilfley type. In all concentrating tables, with which I am familiar,

as the belt of concentratetravelsin the diag onal direction, the heaviest particles, which are nearest to thewash water, shield the lighter particles behind them, from the action of the wash water so that these lighter Specification of Letters Patent. Application filed April 20, 1903. Serial No. 153,562.

the remaining material to theaction of the two bands. the material lmmediately rearranges the I particles tend to mix with the heavier particles, and to overcome this the belt of concentrate must be subjected to the action of the wash water a much longer time than is.

desirable. The material arranging itself into strips or hands, as stated, presents a band of the heaviest material acted upon,

nearest to the force of washwater and the next band of material oflighter gravity di', rectly behind it. However, there will not. be a clear line of divisionbetweenithe bands,

but the second band will overlap the first to a greater or less extent and in the final sep.

aration of the material, this underlap of the first band goes with the second hand and represents a loss: With this general state ment of facts it may be said that my inven- .tIOII has a mam object consisting. of two parts. In the first instance, the object lSwtO remove a portlon of the foremost band of. concentrates and subject the front :wall of:

wash water. In practice, the material come near to the secondhand as is feasible and thereby exposesthe lapping portions ofthe The wash water acting upon same so that a new band of heavy material is formed, and as in the previous case there will be a lapping of the bandsof heavy material and the band adjacent thereto, but the lapping is not so great as before. The

ed to the wash water, and in this manner progressively smaller portions of the heavier valuable material underlap so that in the. final discharge over the tail of the tablea crosswise of the stream of wash water, and

each tapering downward toward: the right Patented A.ug.;4l, 1914;

prlsingthe foremost band is removed as ;:front band may be successively removed and the remaining material successively subjectso as to gradually merge in the remaining a.

portion of the table. As the mineral particles traveling from left to right and by tie-y grees gaming on the waste particles, gradually leave the protection of the ritlles andl crawl out upon the smooth surface,they a1 'e 9 l i veniently be adjusted to the under side of ei als composing these concentrates, etc. ,'and

' subjected more and more to the sweeping.

to prevent loss in this way by providing centrates as rapidly as they are separated,

action of the wash water, and this streamof water'jnot .only finally separates. the .waste from the mineral particles, I as intended, but

also tends to force the mineral partielesdown the inclined lane of the tableso thatv many of the valua leYparticles are washed away.

In order for the wash water to purify the g flfconcentrates on the whole table therefor, there is continuallydestructive action,tothe concentrates the more they are exposed to the wash water. Therefore it is an object of my invention means for the successive dlSGlliLI'gQ of conthus making" it unnecessary forethein to re- 7 main under'the dangerousjactionjof the wash I v water 'any longer than is really necessary. I

i holes in SllltiLlOlG. po's1t1ons along thejl ne' of do this placing one or more discharge concentrates, through which the latter may falland be suitably conveyed to theconcentrates box. "r m-arm receivethe concen trates in] a trough which may very com 7 the table and vibratewith it.

j Snbsidiar 'flp'ortions of thisrimprovement are the arranging of the'openings in groups adjusting: the position of the division end of'the openings; and ,the particular means:

to separate different grades of concentrates;

employed for adjusting such opening,

The reason for adjustirg the division end of the openings is that in operation. there yareycertain 'no nscontrollable} variable factors, as the. quantity of ore delivered per minute, the average v sizes of "grains,- the rangev of sizes, the percentage of concentrat'es, the'proportionsof the various minthe'se non-controllable. factors operate. to

i ,shift the path of the band of concentrates upwardly and downwardly on .the table.

[The non-controllable factors are compensated for by adjustingthe controllable factors,, among which are the 'pos'ition of the operative portion of the opening; the force of the washwatertthe pitch of the,

slope; the shake of the table, (in the sharp- "n essofstroke, the length of stroke, or' the number of strokes')all tables having some means of controlling this factor.

'TlilS'lIlVGIllZlOII includes the combination withthe intermediate discharge openings of any means for controlling one or more of the controllable factors to compensatefor the change of positionsfwhich the non-con trollable factors'tend'to cause, thus dividing theconcentrates as desired] v v second main nnprovement of thisln- VIltlOh consists in locally varylng the wash 7 water 1 according to the conditions of the table so thatxthe concentrates"between the' successive openings shall frece ivejust the proper force ofjwash water. Subsidiary portions of this improvement are the'divid- .inggofthe table, into sections, so that there I shall be little'wash waterzimmed'iately fol-.

lowing a discharge opening, allowingthe concentrates to spread out..longitudlnally,

and then a large amount of wash water to purify them. An arrangement of branch pipes and valves forcontrolling this local .2Ld]LlSl3Il16Ill3,.0f the wash Water, are compre hended within this portion of the invention.

A third main improvement of this invention consists in warping' thesurface of. the I table so thatthe portion of the table cone cerned with'the beginning of the operation,

wherethe settling is desired, shall be nearly flat, but toward thedischargeend the table shall gradually increase in pitch to subject the concentrates to a severer' action of the .wash'water. The means fo'r providing this lwarping Vary with the constructionof the concentrating table to which my improvements are applied. Inthel/Vilfley table, for j instance, I provide this warping adjusting the wedges which operate along the free edge of the tableto raise that edge, as 'de sired. This adjustableine'ans is a subsidiary portion of this improvement.

The variousimprovement's referred to are clearly illustrated in the drawings, which show them as appliedto a WVilfley table. Figure l isla plan of such table embody-f ing the featuresof' several adjustablerdis- .charge openings and the. wash water acting in sections and individually adjustable. ,Fig. '2 is a transverse'section of such table.

Figs. 3 to 6, inclusive, represent-thezpre' "I'erred'form of adjusting the discharge open- ;ing; Fig. 3 being a vertical section length-j la crosssec v tic-n on the line 44 ofjFig. 3; Fig.5 a cross sectionfthrough the bearingiand' Fig. ;6 a cross section throiigh the housing plate around the opening. Fig.7 is a plan of the table illustratingthe warped surface and.

wise of the opening;

the grouping of the discharge holes. Fig.8

Fig. 11 'is' enlarged View of a portion of the mechanism charge o-penings,andFig. '15 is a cross section of such metal end pie'ce.

The table proper is represented by A. It consists of a large' surface shown as' covere'd shown in Fig. 11. Fig; 13-is a cross section through the table showing this 'closingfm'ech anismiFig. 14 is a perspective view of the metal end of the rifhes opposite the disi x by linoleuma, and having upon it, extend LII-05,9 12

ed in parallel manner from the left hand end, the rifiles a, which. extend continuously farther and gradually decreaseiin height to. merge at their right hand ends with the fiat. surface of the table.'

ed so as to be capable of longitudinal move-. ment onflsuitable supporting cross beams 13. This. mounting a is shown as being by roll- The beams B arehinged at b par-- allel with the back edge of the table, while This table A is mounters a.

attheir front ends the beams are supported bywedges C. Theseqwedges are movable upon the foundation D by means of a lever 0, towhichlthe; are connected by a link 0 The Wedges'thus operate to hold the table in an inclined position. Thewedges arese cured to the link c 'by bolts 0 taking through slots in. the link; which allows the wedges to be individually adjusted so as to raise the "front right hand corner of the table. more than the left hand corner, giving it.

1 than toward-the leftg Any suitable mechanism may betemployed for .doing;.this,.-

none being shown, as such mechanisms are common 'and well known'inthe art. This unequal shake of thetabletoward the right causes the particles to travel in that direction betweenthe riflles. As they progress toward the right, the rifiles, decreasing in height, make less of a barrier for the :light particles, and these light particles are again carried'off over the back edge of the table,

the particles which are thus carried off .be-

ing continuouslyheavier toward the right hand end of thetable. Extending along the front edge of the smooth portion of the table andsuspended above it is a pipe F receiving water and arranged to distribute it over the smooth surface of the table and over the right hand portion of the rifiled surface to purify the material. ..No\v, as the materiahwhich islcaught betweenthe ritfles, travels to the rightand then grad-- ually is forced over the rifiles, some ofit clear over the edge of the: table,,other. and

heavier particles being again caught and i againtravehngto the right, and so on in a step-wise. movement, the. comparatively heavy; particles eventually all emerge on the smooth surface of: the'table, and tend,

under the two forces of the wash Water and I waste.

All the heavier partlof the ore and K beneath the same. residue of ore grains passing belowythisi opening passes on,.togetherw1th the acwith the waste.

shake, to. take a diverging diagonal; path toward the lower right hand corner of the table. The front edge of this stream of concentrates, as they are called,.is the heavi-.

,est or very richest. Inoperations upon golclk 1 ore it lnayEbea stream of pure metallic gold next behind this comes a streamof less rich ore, and so on,--the band becominglessrich in concentrates until. it merges into what are known as middlingsyand the rear edge of the middlings stream merges into the A concentrates box (not shown); is, l placed at the right hand corner of the table,

and the inclineof the table, its longitudi gnal shake and the wash waterare so adjusted :that the concentrates pass into this box, and .the middlings into a. box. or trough L be? hind it, (and the waste behind it. Nowto save thep'ure concentrates from action by the .wash'watieroany longer than necessary, :I provide, as heretofore. stated, one iormore dischzu'ge holes .in. the table in advance of ithe extreme discharge, so that as soon as a, reasonable portlon of the concentrates have beerrpurified they drop through the table,

and thelexhausted. residue is submitted to the action; of the wash wateryto be again, treated in like manner. This operation on the successively. exhausted residue is i as heretofore stated one ofthe main features of this invention.

As shown in Fig. 1, the separated concentrates, indicated by G, travel diagonally downward along the front edge ofthe rif-. ffles, passingfirst overthe opening J, and

drop through this opening into a trough The partly exhausted cession thereto comingfrom the riflles far ther down the table,and the additional con-y centrates separated J therefrom pass across another opening,as J through which they. drop into the trough K. Then the. further exhausted residue, with its accretions, again passes on, and. its separated concentrates may pass through another opening, as J This last exhaustedqresiclue, which asses below J is a ain se arated and divi ed at.

the edge of table into the last remnant of concentrates also middlings and waste, and the middlmgs are in onepositlon and the waste in another. The middlings are shown as passing over, the right hand edge of the table next to the concentrates stream.

This arrangement results 1n a great saving ofthe valuable particles of the ore. As

soon as any valuable particles are separated they at oncepasstoa place of safety, wh le under theold arrangementthey were forced to run the gauntlet of many feet of wash waterwith the result that a greater or less portion thereof was lnvarlably carried over If it is desirable to separate the valuable concentrates into tw'o' or inore --grades,=- this may be don'ebyroviding groups of open-. ings,' as' indicated y J 1*. on Fig.7,each opening "ofth'e group being, of course, controlled by 1 own valver the openings being prop 'erly 'ISPa'Ce'd to;' permit the duplication of these" valves; The trough; K 'below" these openings divided;v the front half thereof discharging richer concentrates than the.

rear-half." This division of the valuabl'e com cejxitra'tes may be extended to any'refiner' nent- 5;Now,= to attainthe best results with f o enings; it" is necessaryto govern the lportion-o f the'eoncentrates passing into the-same with reference to'the 'gradeof ore, because the division-dine or lines between the concentrates and other rades of'material tends to vary it's position from time to-time." Idothis in" the presentrinvention by either one; of two" methods; fir st, by having openings ina' fixed position 1 and holding the division'- line 'steady'tosuit position of openings by' adjusting the slope or quantity of' 'wash water, orsharpness .of stroke or length of stroke,,or number of strokes per minuteall "tables being provided with mechanical means for making one ormore of theseadjustmentsl Secondly, I may accomplish this allowing division line to vary and shifting the positionof the-divisionend of each openingtotcorrespond. I show here with twokinds of such adjustable openings.

For instance: Fig. 10 shows theopening's '3' lengthwise, as J, while'in the other figures they are crosswise. ,In-either case, I have provided :beneath" the opening adjustablenieans 'forpartly closing it,'so as to shift-the division end of the op'eningfaccording t'o'the position of the division line, this position changing "with the quantity of ore per minute, the average size of grains, the range of grain sizes, the percentage of concentrates, the proportions of the varlous minerals com-.

posing "these concentrates, etc, etc!" One adjustable nieans for shifting the division end of an o ening in the table consists of a suitable gate movable beneath that opening.

s. 3 "to 6,illustrate themechanism where the gate is rotatable; Figs; 11 to 13 llltlSt iate' it where the gate'is longitudinally slldable;

Referring, first; to Figs. 3 to 6, inclusive, the openingl inflthe table A is bounded by'the housing plate" j, having through it'afrectangular opening 9', and having on its under side a ,CQnCa-vesurface; Beneath this con,

cave surface is a cylinder y' provided with a v spiral'edge and having axles j ,y' journaled in' blocks 1 loosely carried mule housing-f beneath the table; These blocks 7' are'pressed upwardby springs j to' cause the cylinder to substantially" engagevthe concave surfaceof the housing plate at all, times, but to yield downward if necessary as nsmall particles Yofmaterial may work in between it and the plate, 7 cylinder :j 1is' turned o'n-its axis the opening it entirely closed. Now," if the cylinder lbe front end until, when the cylinder has been means -for ;rotating-'the cylinder; Whichfl ping through the" cylinder and discharges :catingwith this passage-way, conveys Water therefor tothe interior'-:-of' fthe cylinder to afiush it out. This water,to'gether-' with wt.

5 at the fend'thereof."

jthe constructionillustrated by Figs. 10 to .15 inclusive,'the'o-penings J are longitudt lnal. They are likewise made in a housing jrifii'e j. This metal riffle bridges an-open ithe gate i isadaptedtoitravel to unclose fithe opening.- This gate is pressed' u'p'ward iiIltO place by springs j whichrestupona' {This causes the gate totravel with therack ;bar; but allows it"to adjust itself yieldingly Itv will be readily; seen that as the rotated in a left hand directiontheopening will? -be-gradua11yunclosed from" its Qter entering the upper end ofthetrough lthrough a pipe (governed by a valve'ft) causes the concentrates passing through any. iof -the discharge openings in the table, to- ;travel along the trough'K and be delivered a I Another adjustablewopening is shown in Lto the housing plate j f fMeshingwith the.

7' is gradually closed. Figs. 3' and 41 show rotated a littleless than' all' the way aro11nd, the I o-peningvgwill' ;,be entirely. open; The have employed, consists of amnion f 'on'the shaft of. the cylinder meshing with the gear;

j ona shaftj which'eiztends' to'the front of I i the table and-therereceivesa hand wheel: .1'

plate 7' which alineswith the end of a metal iing through the-tabl'e-of the same width asfthe opening J and its higher end merges :with the ordinary wooden rifilea'of'the ta?" jble; The'inetal riflie is used. so as to leave an opening beneath it. Into'this opening slidablerack bar 3' which has arms j v gsli'dable onledges on the housin g.j This 1 ihdusing extends lengthwise approximately itivice-the ,length of the gate 7' the 'left' hand :half of the housing being under the,

The gate, is held to the :rack bar by pins 7' carried by'the'rackbarj gan'd .eXtending into openings injthe'zga-te." l

track b ar'is a pinion y' onashaft j oul'f waterimmediately following each opening naled inisuitable hearings. 9' carried bythe housing j This shaftj can. be rotated inany suitable manner, as by ahand wheel,

wherefore the gateisshifted to uncover the opening, as desired. covers the opening, it travels toward the left hand end .ofthetable passing beneath the metal end j of the riflie.

It :will be seenfrom the above description that either in the form of adjustmentshown in Figs;*3 to 6 orin Figs. 11 to 13, a simple rotation of the .hand wheel varies the discharge opening, the hand wheelbeing thereafter locked by any suitable means, asthe progresses to the other end of the table, the

operation becomes moreand morekone of separation, and as the material on the table is thus continually heavier toward the right and hence has more of a tendency to :travel in; a path continually approaching av line parallel. with the 'rifiles," I counteract this by making the table continuously steeper to the right, thus givinga warped surface. Since this warp is gradual it gives a gradually in: creasing slope for each successive operation, which has a particular advantage, owing to theafact that each section now operates upon the exhausted residue of the preceding section due to my intermediate discharge open: ings; It :is to be noted that the amount ofwarping of the surface, and the amount of general incline given to it, is very slight,1

beingexaggerated herein for the purposes of, illustration. Now as the portions of the table nearest the discharge end need the strongest current in the wash water as the particles are heavier; I provide means for locally regulatingthe flow of the: wash water according to the section of the table which it feeds. I accomplish this by extending, downward from the main wash the exhausted residue of concentrates, aftera. portion I has been removed by dropping through one of the openings, should be given opportunity tospread out so that the heavy and rich ,particleswill not be washed away with the lighter ones, I arrangethe wash When the gate un-.

so that it. shall be very slight in flow, being preferable just enough to keep the material wet. This allows the material to travelout longitudinally of the table, the heavy particlesgainingon thelight particles under the influence of the shake. 1 Then, before the next discharge opening is reached, the concentrates encounterwvash water coming in greater force from another branch f", which washes away the light particles and gives to the band of concentrates a diagonally dOWIl'. ward direction causing them to pass over the next opening through which the rich portiondrops, after this the residue may againencounter first, a slightfiow of water and then a large force thereofu, This sectional operation may be facilitatedby dividing the table into physical sections by transverse slats on the table surface, as a a;

Of these slats a are directly at opposite the discharge openings and a are intermediate. Another modeof washing so asito spread out the partly exhausted residue before sepa aratingit by the full strength of wash water is to graduate'the strength of wash water over :the limits of eachzsection between discharge points so that it is very weak at the beginning and of .full strength at theend. This may be effected by a large number of small valves adjusted to this end or by hav inga single branch pipeioverueach section with discharge apertures in the pipe of graded size increasing toward the end of the section.

. .By regulating the position ofthe division end of the dischargeopening or by varying.

theforce of thewash water or the other factors which tend to drive the concentrates rears ward, I can make just that. portion of the belt of concentrates which is ofthe desired richness pass over and drop'into a discharge opening. a The successive adjustable. discharge openings, the regulated sectionally operating wash water, and the warp of the table all cooperate to produce a separation andconcentrati'onof the ore which is far in advance of anything heretoforedevised with which I am familiar, and whichis wellnigh perfect, resultingin saving substantially all the valuable portions of the ore.

Having described my invention, Iclaim:

1. A concentrating table having a separating portion which is free of riilles combined with means for imparting differential lengthwise vibration to said table, and means for delivering a forceful sheet of wash water onto said table ina direction which is trans verse to the direction of vibration, and is toward the rear side of said table, and means for removingthe unlappedpart of the front band, said means being located at a point such that after the stated part of said band has been removed the wash water acting, on

' the rear side of saidtabhe; said table having thronghi't a plurality of slots Whose rear ends are progressively nearer the rear edge of the table as they are nearer the delivery end thereof, arfd said slotslbein'g in the :path

.- off the u'hlapbed part 01153 of the front band,

and there beihg a suflicient distance between said slots to material by t e action of the "Wash water while -said material is traveling the distance between-said slots. I

l '3. A concentrating table, a *sepa rating ,pbrtion which is free of. es, smeans i for *diflferenti'ahy vibratihg the table in one fu'l sheet of Wash'wate'r onto said table in a dihect-ion which is transve'rse to the direct-10in o f vibration and istdvvahd the rear side 10f said table, said table having through a p'iuraiity of slots Whose rear-ends are lprogressively nearer the rear edge oi the table as they are near the delivery e'n'd thereof, and*sai'd'-'s1 ots being in the path "of the unia lapped part-ionlyof the front band, and

there *being a suflicient distance between said slots :to permit the Frebandi-ng (of the 'material by the aetion'of the Wash wateruwvhile said material- 'is traveling the distance between the S1'OtS,-aIid 'means rfor varying the,

position oif-jthe rearends 0f said slots.

, 4. A vibrating "concentrating table having a vvash Water supply and v a separating, zportibn wherein the previously settled mineral is "divided into bands, said separating portion "being provided with successive groups of discharge openings -"on that side of the path 012' 'movement'iof the mineral nearest the Wash Water supply, one of "the members of eachwgroup being advanced somewhat nearer than. therest of the group toward the Wash "watersupply', each opening having am'eans f0r'contro11in-gthe entrance-of m-inra'lthereto. r i I v 5. A 5 'o'n-centrating table having an opening in, it, cylindrical =gate ?for partially closing'said opening, a spring for yieldingly holding saidflgate beneath the "opning, and means fornioving said-gate. e

'6. A concentrating table, having an "open ing in it, aey1indrica1 gatebeneath the' openineg 'for partially closing it, =one' or more springs :yilciihgly holdin -said gate, a "1'0- tatable shaft, and a agear "edn'nection between the same and "said agate, all "of said parts being carried by the table.

"r. A coneentratingtable havingan o en ing'in it, and a member having a spirally disposed edge for controlling the position of that. end of the opening which is within the concentrate band. I i

8. -A concentrating; table having "an "open ing in it, .a rotatable vmen'nher having a spirally disposed edge for controlling the size ofsa'id o'p'ening, and a rotatable shaft for turnihgsai'd -n1en1'ber. v a

9. concentrating table, having an open ing in it, a housing sui'rou'ndiilig annexes-1 ing and having amneav under; st-1r ace; 'a rotatable member having .a spirahy disposed edge spring-pressed against said-surface, and means for rotating 'said member;

' 10.. A concentrating table, having an open= ing in it, a housing surrounding-said {open-e ing, bearing blocks ioos'ely earnedub said housing, a member having a spiral-1 1 disposed edge joilrnaled in Mocks,-

springs beneath said bearing blockstending to elevate the member, and means for-frota ta in'gqsaidmember. I i :11. FA concentrat ng table, having andpening it, a housing harried by "said table beneath ls'aid opening, said housing hav-ing' a ptate Wh-ih 'dfornrs the border ofcthe open--- ing; the until-er"?side -of said plate being .c'on'- cave, "a member havi'ng' a spirally idisposed edge *canri'ed "by said housing,- sprmgs fo'rc-I ing said -sero11 tovvardrsaid 'concave" surface,

and a rotatable sh'a'it connected with said member i A 'eoncentrafiing 'tahle, having anbpening in it, a housing plate surrounding-said opening being (concave on itsnnderside, a housing beneath said plate, bearing b1-oe1rsin said housing, "a "spiral 'edgedf gate ejou'rwm n'al'e'd in said :bearin 'b10eks,springs acting onsaid blocks tO..Ty11diI1-g1y hold the gate against the concave surf-ace, nne 'of the .j'ourna-ls of thegate beingho11oW,' a-IpassageWay in the housing "communicating *there'With; and a rotatable gshztftconnmcted withzfthe otli'erijournalof'theagate; v a I 13; Ina concentrating table, the combination of a table having on its pupper surface longitudinal riffie'sand i cross slats to divide it into difl'ere'nt sections, a system of wash Water plplng, and means 'aor radiating 1t for thedifi'erentsections"of thetable;

14. Incombination with a vibrating "con centrating table, means for dis'charging a] forceful sheet 0f Wash water onto said table in 'adirectiontransverse to the direction --o-f vibration of the table, said table :bein pro vided with openings in it, cross slats =-'carried by the'table "substantially in line wvith the openings, "and-means :for independently regulating *the Wash water "Within Fthe sectionsdefined by said s'lbts.

-15. In "a *concentr'a'ting table/the combina'e tion "of a table having bpenings in it, =:cross slats on the upper surface of the table terminating substantially at said 0penings,intermedjateslats between the cross slats, said slats dlvidlng the table into two sections be- EDMUND B. KIRBY.

tween the openings, :1 system of Wash water WVitnesses: 5 piping, and means for governing the flow (1W, JENKINS, therefrom locally for each of said sections. H. J. DARBY.

Copies of this patent may be, obtained ,for five centseach, by addressingthe Commissionerof Patents, Washington, D. G. 

